FIGS. 1 and 2 are respectively a front elevation and a perspective view of a typical conventional cable window lift system generally indicated by reference numeral 20. The system 20 includes a window regulator rail 22 along which runs a lift plate 24 which in turn is attached to a window glass (not shown). A top pulley 26 and a bottom pulley 28 are mounted to opposite ends of the rail 22. A cable 30 is attached to the lift plate 24 and extends over the top and bottom pulleys, 26 and 28 respectively. The cable 30 is operably connected to a window regulator motor 32 which causes the cable 30 to move longitudinally and in turn causes the lift plate 24 and any window attached thereto to move along the rail 22.
The conventional cable window lift systems 20 tend to be vehicle specific. As the window glass moves with the lift plate 24, and as window glass in automobiles is typically curved, the rail 22 must have a curvature corresponding to the glass and this will vary from vehicle to vehicle and from window to window within a given vehicle. Furthermore the rail must have a length consistent with the window travel which will vary from model to model, for example, a two door model versus a four door model.
Overall length of the rail 22 and top and bottom pulleys, 26 and 28 respectively, is also a concern as the vertical height available within, for example a door, is limited by the available space. The conventional cable window lift systems 20 have an overall height of approximately that of the travelled portion of the rail 22 plus the height of the top pulley 26 and that of the bottom pulley 28. The placement of the top pulley 26 and bottom pulley 28 on the rail 22, and typically in a plane parallel to the lift plate travel direction limits the travel of the lift plate 24 to the distance between the pulleys. Any attempt at further travel will result in the lift plate 24 striking either the top or bottom pulley 26 and 28 respectively.